A. Background Regarding Bisphosphonates
The methods and compositions of the invention comprise a bisphosphonate. The bisphosphonates of the invention are also referred to interchangeably as the “compounds of bisphosphonate.” “Bisphosphonates are a class of drugs used to strengthen bone. Bone is in a constant state of remodeling, whereby new bone is laid down by cells called osteoblasts while old bone is removed by cells called osteoclasts. Bisphosphonates inhibit bone removal (resorption) by the osteoclasts. Bisphosphonates are used to treat osteoporosis and the bone pain from diseases such as metastatic breast cancer, multiple myeloma, and Paget's disease. The bisphosphonates include FOSAMAX® (alendronate sodium), AREDIA® (pamidronate sodium), ACTONEL® (risedronate sodium), BONIVA® (ibandronate sodium), DIDRONEL® (etidronate), and ZOMETA® (zolendronic acid). The compounds are also used to treat osteoporosis that is caused by treatment with a corticosteroid.
1. Background Regarding Alendronate
Alendronate sodium, which is commercially marketed as FOSAMAX®, is a bisphosphonate that acts as a specific inhibitor of osteoclast-mediated bone resorption. Bisphosphonates are synthetic analogs of pyrophosphate that bind to the hydroxyapatite found in bone. Alendronate sodium is chemically described as (4-amino-1-hydroxybutylidene) bisphosphonic acid monosodium salt trihydrate.
The empirical formula of alendronate sodium is C4H12NNaO7P2.3H2O and its formula weight is 325.12. The structural formula is:

Alendronate sodium is a white, crystalline, nonhygroscopic powder. It is soluble in water, very slightly soluble in alcohol, and practically insoluble in chloroform.
FOSAMAX® tablets for oral administration (Merck & Co. of Rahway, N.J.) contain 6.53, 13.05, 45.68, 52.21 or 91.37 mg of alendronate monosodium salt trihydrate, which is the molar equivalent of 5, 10, 35, 40 and 70 mg, respectively, of free acid, and the following inactive ingredients: microcrystalline cellulose, anhydrous lactose, croscarmellose sodium, and magnesium stearate. FOSAMAX® 10 mg tablets also contain carnauba wax.
Disadvantages of FOSAMAX® include very poor bioavailability, fed/fasted variability in absorption, and significant gastrointestinal irritation.
As to the clinical pharmacological mechanism for alendronate sodium, animal studies have indicated the following mode of action. At the cellular level, alendronate shows preferential localization to sites of bone resorption, specifically under osteoclasts. The osteoclasts adhere normally to the bone surface but lack the ruffled border that is indicative of active resorption. Alendronate does not interfere with osteoclast recruitment or attachment, but it does inhibit osteoclast activity. Studies in mice on the localization of radioactive [3H]alendronate in bone showed about 10-fold higher uptake on osteoclast surfaces than on osteoblast surfaces. Bones examined 6 and 49 days after [3H]alendronate administration in rats and mice, respectively, showed that normal bone was formed on top of the alendronate, which was incorporated inside the matrix. While incorporated in bone matrix, alendronate is not pharmacologically active. Thus, alendronate must be continuously administered to suppress osteoclasts on newly formed resorption surfaces. Histomorphometry in baboons and rats showed that alendronate treatment reduces bone turnover (i.e., the number of sites at which bone is remodeled). In addition, bone formation exceeds bone resorption at these remodeling sites, leading to progressive gains in bone mass.
As to the pharmacokinetics of absorption of alendronate, relative to an intravenous (IV) reference dose, the mean oral bioavailability of alendronate in women was 0.64% for doses ranging from 5 to 70 mg when administered after an overnight fast and two hours before a standardized breakfast. Oral bioavailability of the 10 mg tablet in men (0.59%) was similar to that in women when administered after an overnight fast and 2 hours before breakfast.
A study examining the effect of timing of a meal on the bioavailability of alendronate was performed in 49 postmenopausal women. Bioavailability was decreased by approximately 40% when 10 mg alendronate was administered either 0.5 or 1 hour before a standardized breakfast, when compared to dosing 2 hours before eating. In studies of treatment and prevention of osteoporosis, alendronate was effective when administered at least 30 minutes before breakfast.
Bioavailability was negligible whether alendronate was administered with or up to two hours after a standardized breakfast. Concomitant administration of alendronate with coffee or orange juice reduced bioavailability by approximately 60%.
If oral administration of the bisphosphonate is desired, relatively high doses must be administered to compensate for the low bioavailability from the gastrointestinal tract. To offset this low bioavailability, it is generally recommended that the patient take the bisphosphonate on an empty stomach and fast for at least 30 minutes afterwards. However, many patients find the need for such fasting on a daily basis to be inconvenient. Moreover, oral administration has been associated with adverse gastrointestinal effects, especially those relating to the esophagus. See Fleisch, Bisphosphonates In Bone Disease, From the Laboratory to the Patient, 2nd Edition, Pantheon Publishing (1995). These effects appear to be related to the irritant potential of the bisphosphonate in the esophagus, a problem which is exacerbated by the presence of refluxed gastric acid. For example, the bisphosphonate, pamidronate has been associated with esophageal ulcers. See E. G. Lufkin et al., Pamidronate: An Unrecognized Problem in Gastrointestinal Tolerability, Osteoporosis International, 4: 320–322 (1994), which is incorporated by reference herein in its entirety. Although not as common, the use of alendronate has been associated with esophagitis and/or esophageal ulcers. See P. C. De Groen, et al., Esophagitis Associated With The Use Of Alendronate, New England Journal of Medicine, vol. 335, no. 124, pp. 1016-1021 (1996), D. O. Castell, Pill Esophagitis—The Case of Alendronate, New England Journal of Medicine, vol. 335, no. 124, pp. 1058-1059 (1996), and U. A. Liberman et al., Esophagitis and Alendronate, New England Journal of Medicine, vol. 335, no. 124, pp. 1069-1070 (1996), which are incorporated by reference herein in their entirety. The degree of adverse gastrointestinal effects of bisphosphonates has been shown to increase with increasing dose. See C. H. Chestnut et al., Alendronate Treatment of the Postmenopausal Osteoporotic Woman: Effect of Multiple Dosages on Bone Mass and Bone Remodeling, The American Journal of Medicine, vol. 99, pp. 144-152, (August 1995, which is incorporated by reference herein in its entirety. Also, these adverse esophogeal effects appear to be more prevalent in patients who do not take the bisphosphonate with an adequate amount of liquid or who lie down shortly after dosing, thereby increasing the chance for esophageal reflux.
The interference with the bioavailability of alendronate sodium resulting from eating and drinking, and the adverse gastrointestinal effects of bisphosphonates are reflected in patient information for taking once weekly FOSAMAX® tablets. The guidelines prescribe that after swallowing a FOSAMAX® tablet one must wait at least 30 minutes before taking food, beverage or other medicaments of the day. The guidelines further require that FOSAMAX® tablets are not taken at bedtime or before getting up for the day. In addition, the patient must stay fully upright after taking FOSAMAX® for at least 30 minutes and after the first food of the day.
U.S. Pat. Nos. 5,616,571, 5,994,329, 6,015,801, 6,225,294, 6,333,316, 6,432,932, 6,465,443 and 6,544,967, all to Daifotis et al., U.S. Pat. No. 4,621,077 to Rosoni et al., U.S. Pat. Nos. 5,358,941, 5,681,590, 6,090,410 and 6,194,004, all to Bechard et al. and U.S. Pat. Nos. 5,849,726 and 6,008,207, both to Brenner et al., relate to the use of bisphosphonates in the treatment of abnormal bone resorption. These United States Patents are incorporated by reference.
2. Background Regarding Pamidronate
Pamidronate disodium, commercially available as AREDIA®, is a bone-resorption inhibitor available in 30-mg, 60-mg, or 90-mg vials for intravenous administration. Each 30-mg, 60-mg, and 90-mg vial contains, respectively, 30 mg, 60 mg, and 90 mg of sterile, lyophilized pamidronate disodium and 470 mg, 400 mg, and 375 mg of mannitol, USP. The pH of a 1% solution of pamidronate disodium in distilled water is approximately 8.3. AREDIA®, a member of the group of chemical compounds known as bisphosphonates, is an analog of pyrophosphate. Pamidronate disodium is designated chemically as phosphonic acid (3-amino-1-hydroxypropylidene) bis-, disodium salt, pentahydrate, (APD), and its structural formula is:

Pamidronate disodium is a white-to-practically-white powder. It is soluble in water and in 2N sodium hydroxide, sparingly soluble in 0.1N hydrochloric acid and in 0.1N acetic acid, and practically insoluble in organic solvents. Its molecular formula is C3H9NO7P2Na2.5H2O and its molecular weight is 369.1. Inactive ingredients for AREDIA® include mannitol, USP, and phosphoric acid (for adjustment to pH 6.5 prior to lyophilization).
Side effects of pamidronate include pain at the site of catheter insertion (including redness, swelling or induration, and pain on palpation). Side effects also include gastrointestinal pain, including abdominal pain, anorexia, constipation, nausea, vomiting, diarrhea, dyspepsia, gastrointestinal hemorrhage, and stomatitis.
3. Background Regarding Risedronate
ACTONEL® (risedronate sodium tablets) is a pyridinyl bisphosphonate that inhibits osteoclast-mediated bone resorption and modulates bone metabolism. Each ACTONEL® tablet for oral administration contains the equivalent of 5, 30, or 35 mg of anhydrous risedronate sodium in the form of the hemi-pentahydrate with small amounts of monohydrate. The empirical formula for risedronate sodium hemi-pentahydrate is C7H10NO7P2Na .2.5 H2O. The chemical name of risedronate sodium is [1-hydroxy-2-(3-pyridinyl)ethylidene]bis[phosphonic acid] monosodium salt. The chemical structure of risedronate sodium hemi-pentahydrate is the following:

Risedronate sodium is a fine, white to off-white, odorless, crystalline powder. It is soluble in water and in aqueous solutions, and essentially insoluble in common organic solvents. Inactive ingredients in ACTONEL® include crospovidone, ferric oxide red (35-mg tablets only), ferric oxide yellow (5 and 35-mg tablets only), hydroxypropyl cellulose, hydroxypropyl methylcellulose, lactose monohydrate, magnesium stearate, microcrystalline cellulose, polyethylene glycol, silicon dioxide, and titanium dioxide.
Side effects of risedronate include gastrointestinal irritation.
4. Background Regarding Ibandronate
Ibandronate sodium is commercially sold as BONIVA® . BONIVA® is a nitrogen-containing bisphosphonate that inhibits osteoclast-mediated bone resorption. The chemical name for ibandronate sodium is 3-(N-methyl-N-pentyl) amino-1-hydroxypropane-1,1-diphosphonic acid, monosodium salt, monohydrate, with the molecular formula C9H22NO7P2Na. H2O and a molecular weight of 359.24. Ibandronate sodium is a white- to off-white powder. It is freely soluble in water and practically insoluble in organic solvents. Ibandronate sodium has the following structural formula:

BONIVA® is available as a white, oblong, 2.5-mg film-coated tablet for daily oral administration or as a white, oblong, 150-mg film-coated tablet for once-monthly oral administration. One 2.5-mg film-coated tablet contains 2.813 mg ibandronate monosodium monohydrate, equivalent to 2.5 mg free acid. One 150-mg film-coated tablet contains 168.75 mg ibandronate monosodium monohydrate, equivalent to 150 mg free acid. BONIVA® also contains the following inactive ingredients: lactose monohydrate, povidone, microcrystalline cellulose, crospovidone, purified stearic acid, colloidal silicon dioxide, and purified water. The tablet film coating contains hypromellose, titanium dioxide, talc, polyethylene glycol 6000, and purified water.
Side effects of ibandronate include gastrointestinal irritation.
5. Background Regarding Etidronate
Etidronate is commercially available as DIDRONEL® (etidronate disodium). DIDRONEL® tablets contain either 200 mg or 400 mg of etidronate disodium, the disodium salt of (1-hydroxyethylidene) diphosphonic acid, for oral administration. This compound, also known as EHDP, regulates bone metabolism. It is a white powder, highly soluble in water, with a molecular weight of 250 and the following structural formula:
Inactive ingredients in DIDRONEL® tablets include magnesium stearate, microcrystalline cellulose, and starch.
Side effects of DIDRONEL® include gastrointestinal irritation, which can affect the dosage that can be administered. Also, because of potential gastrointestinal irritation, patients are advised to avoid consuming food within two hours of dosing.
6. Background Regarding Zolendronate
Zolendronate is commercially available as ZOMETA® (zolendronic acid). ZOMETA® contains zoledronic acid, a bisphosphonic acid which is an inhibitor of osteoclastic bone resorption. Zoledronic acid is designated chemically as (1-Hydroxy-2-imidazol-1-yl-phosphonoethyl) phosphonic acid monohydrate and its structural formula is
Zoledronic acid is a white crystalline powder. Its molecular formula is C5H10N2O7P2. H2O and its molar mass is 290.1 g/Mol. Zoledronic acid is highly soluble in 0.1N sodium hydroxide solution, sparingly soluble in water and 0.1N hydrochloric acid, and practically insoluble in organic solvents. The pH of a 0.7% solution of zoledronic acid in water is approximately 2.0.
ZOMETA® (zoledronic acid) Injection is available in vials as a sterile liquid concentrate solution for intravenous infusion. Each 5-mL vial contains 4.264 mg of zoledronic acid monohydrate, corresponding to 4 mg zoledronic acid on an anhydrous basis. Inactive ingredients in ZOMETA® include mannitol, USP, as bulking agent, water for injection and sodium citrate, USP, as buffering agent.
Intravenous administration of ZOMETA® has been most commonly associated with fever. Gastrointestinal reactions such as nausea and vomiting have been reported following administration of ZOMETA®. Local reactions at the infusion site, such as redness or swelling, were also observed.
B. Background Regarding Nanoparticulate Active Agent Compositions
Nanoparticulate active agent compositions, first described in U.S. Pat. No. 5,145,684 (“the '684 patent”), comprise particles of a poorly soluble therapeutic or diagnostic agent having adsorbed onto or associated with the surface thereof a non-crosslinked surface stabilizer. The '684 patent also describes methods of making such nanoparticulate active agent compositions but does not describe compositions comprising bisphosphonates in nanoparticulate form. Methods of making nanoparticulate active agent compositions are described, for example, in U.S. Pat. Nos. 5,518,187 and 5,862,999, both for “Method of Grinding Pharmaceutical Substances;” U.S. Pat. No. 5,718,388, for “Continuous Method of Grinding Pharmaceutical Substances;” and U.S. Pat. No. 5,510,118 for “Process of Preparing Therapeutic Compositions Containing Nanoparticles.”
Nanoparticulate active agent compositions are also described, for example, in U.S. Pat. No. 5,298,262 for “Use of Ionic Cloud Point Modifiers to Prevent Particle Aggregation During Sterilization;” U.S. Pat. No. 5,302,401 for “Method to Reduce Particle Size Growth During Lyophilization;” U.S. Pat. No. 5,318,767 for “X-Ray Contrast Compositions Useful in Medical Imaging;” U.S. Pat. No. 5,326,552 for “Novel Formulation For Nanoparticulate X-Ray Blood Pool Contrast Agents Using High Molecular Weight Non-ionic Surfactants;” U.S. Pat. No. 5,328,404 for “Method of X-Ray Imaging Using Iodinated Aromatic Propanedioates;” U.S. Pat. No. 5,336,507 for “Use of Charged Phospholipids to Reduce Nanoparticle Aggregation;” U.S. Pat. No. 5,340,564 for “Formulations Comprising Olin 10-G to Prevent Particle Aggregation and Increase Stability;” U.S. Pat. No. 5,346,702 for “Use of Non-Ionic Cloud Point Modifiers to Minimize Nanoparticulate Aggregation During Sterilization;” U.S. Pat. No. 5,349,957 for “Preparation and Magnetic Properties of Very Small Magnetic-Dextran Particles;” U.S. Pat. No. 5,352,459 for “Use of Purified Surface Modifiers to Prevent Particle Aggregation During Sterilization;” U.S. Pat. Nos. 5,399,363 and 5,494,683, both for “Surface Modified Anticancer Nanoparticles;” U.S. Pat. No. 5,401,492 for “Water Insoluble Non-Magnetic Manganese Particles as Magnetic Resonance Enhancement Agents;” U.S. Pat. No. 5,429,824 for “Use of Tyloxapol as a Nanoparticulate Stabilizer;” U.S. Pat. No. 5,447,710 for “Method for Making Nanoparticulate X-Ray Blood Pool Contrast Agents Using High Molecular Weight Non-ionic Surfactants;” U.S. Pat. No. 5,451,393 for “X-Ray Contrast Compositions Useful in Medical Imaging;” U.S. Pat. No. 5,466,440 for “Formulations of Oral Gastrointestinal Diagnostic X-Ray Contrast Agents in Combination with Pharmaceutically Acceptable Clays;” U.S. Pat. No. 5,470,583 for “Method of Preparing Nanoparticle Compositions Containing Charged Phospholipids to Reduce Aggregation;” U.S. Pat. No. 5,472,683 for “Nanoparticulate Diagnostic Mixed Carbamic Anhydrides as X-Ray Contrast Agents for Blood Pool and Lymphatic System Imaging;” U.S. Pat. No. 5,500,204 for “Nanoparticulate Diagnostic Dimers as X-Ray Contrast Agents for Blood Pool and Lymphatic System Imaging;” U.S. Pat. No. 5,518,738 for “Nanoparticulate NSAID Formulations;” U.S. Pat. No. 5,521,218 for “Nanoparticulate Iododipamide Derivatives for Use as X-Ray Contrast Agents;” U.S. Pat. No. 5,525,328 for “Nanoparticulate Diagnostic Diatrizoxy Ester X-Ray Contrast Agents for Blood Pool and Lymphatic System Imaging;” U.S. Pat. No. 5,543,133 for “Process of Preparing X-Ray Contrast Compositions Containing Nanoparticles;” U.S. Pat. No. 5,552,160 for “Surface Modified NSAID Nanoparticles;” U.S. Pat. No. 5,560,931 for “Formulations of Compounds as Nanoparticulate Dispersions in Digestible Oils or Fatty Acids;” U.S. Pat. No. 5,565,188 for “Polyalkylene Block Copolymers as Surface Modifiers for Nanoparticles;” U.S. Pat. No. 5,569,448 for “Sulfated Non-ionic Block Copolymer Surfactant as Stabilizer Coatings for Nanoparticle Compositions;” U.S. Pat. No. 5,571,536 for “Formulations of Compounds as Nanoparticulate Dispersions in Digestible Oils or Fatty Acids;” U.S. Pat. No. 5,573,749 for “Nanoparticulate Diagnostic Mixed Carboxylic Anydrides as X-Ray Contrast Agents for Blood Pool and Lymphatic System Imaging;” U.S. Pat. No. 5,573,750 for “Diagnostic Imaging X-Ray Contrast Agents;” U.S. Pat. No. 5,573,783 for “Redispersible Nanoparticulate Film Matrices With Protective Overcoats;” U.S. Pat. No. 5,580,579 for “Site-specific Adhesion Within the GI Tract Using Nanoparticles Stabilized by High Molecular Weight, Linear Poly(ethylene Oxide) Polymers;” U.S. Pat. No. 5,585,108 for “Formulations of Oral Gastrointestinal Therapeutic Agents in Combination with Pharmaceutically Acceptable Clays;” U.S. Pat. No. 5,587,143 for “Butylene Oxide-Ethylene Oxide Block Copolymers Surfactants as Stabilizer Coatings for Nanoparticulate Compositions;” U.S. Pat. No. 5,591,456 for “Milled Naproxen with Hydroxypropyl Cellulose as Dispersion Stabilizer;” U.S. Pat. No. 5,593,657 for “Novel Barium Salt Formulations Stabilized by Non-ionic and Anionic Stabilizers;” U.S. Pat. No. 5,622,938 for “Sugar Based Surfactant for Nanocrystals;” U.S. Pat. No. 5,628,981 for “Improved Formulations of Oral Gastrointestinal Diagnostic X-Ray Contrast Agents and Oral Gastrointestinal Therapeutic Agents;” U.S. Pat. No. 5,643,552 for “Nanoparticulate Diagnostic Mixed Carbonic Anhydrides as X-Ray Contrast Agents for Blood Pool and Lymphatic System Imaging;” U.S. Pat. No. 5,718,388 for “Continuous Method of Grinding Pharmaceutical Substances;” U.S. Pat. No. 5,718,919 for “Nanoparticles Containing the R(-)Enantiomer of Ibuprofen;” U.S. Pat. No. 5,747,001 for “Aerosols Containing Beclomethasone Nanoparticle Dispersions;” U.S. Pat. No. 5,834,025 for “Reduction of Intravenously Administered Nanoparticulate Formulation Induced Adverse Physiological Reactions;” U.S. Pat. No. 6,045,829 “Nanocrystalline Formulations of Human Immunodeficiency Virus (HIV) Protease Inhibitors Using Cellulosic Surface Stabilizers;” U.S. Pat. No. 6,068,858 for “Methods of Making Nanocrystalline Formulations of Human Immunodeficiency Virus (HIV) Protease Inhibitors Using Cellulosic Surface Stabilizers;” U.S. Pat. No. 6,153,225 for “Injectable Formulations of Nanoparticulate Naproxen;” U.S. Pat. No. 6,165,506 for “New Solid Dose Form of Nanoparticulate Naproxen;” U.S. Pat. No. 6,221,400 for “Methods of Treating Mammals Using Nanocrystalline Formulations of Human Immunodeficiency Virus (HIV) Protease Inhibitors;” U.S. Pat. No. 6,264,922 for “Nebulized Aerosols Containing Nanoparticle Dispersions;” U.S. Pat. No. 6,267,989 for “Methods for Preventing Crystal Growth and Particle Aggregation in Nanoparticle Compositions;” U.S. Pat. No. 6,270,806 for “Use of PEG-Derivatized Lipids as Surface Stabilizers for Nanoparticulate Compositions;” U.S. Pat. No. 6,316,029 for “Rapidly Disintegrating Solid Oral Dosage Form,” U.S. Pat. No. 6,375,986 for “Solid Dose Nanoparticulate Compositions Comprising a Synergistic Combination of a Polymeric Surface Stabilizer and Dioctyl Sodium Sulfosuccinate;” U.S. Pat. No. 6,428,814 for “Bioadhesive Nanoparticulate Compositions Having Cationic Surface Stabilizers;” U.S. Pat. No. 6,431,478 for “Small Scale Mill;” U.S. Pat. No. 6,432,381 for “Methods for Targeting Drug Delivery to the Upper and/or Lower Gastrointestinal Tract;” U.S. Pat. No. 6,582,285 for “Apparatus for Sanitary Wet Milling;” and U.S. Pat. No. 6,592,903 for “Nanoparticulate Dispersions Comprising a Synergistic Combination of a Polymeric Surface Stabilizer and Dioctyl Sodium Sulfosuccinate;” U.S. Pat. No. 6,656,504 for “Nanoparticulate Compositions Comprising Amorphous Cyclosporine;” U.S. Pat. No. 6,742,734 for “System and Method for Milling Materials;” U.S. Pat. No. 6,745,962 for “Small Scale Mill and Method Thereof;” U.S. Pat. No. 6,811,767 for “Liquid droplet aerosols of nanoparticulate drugs;” U.S. Pat. No. 6,908,626 for “Compositions having a combination of immediate release and controlled release characteristics;” U.S. Pat. No. 6,969,529 for “Nanoparticulate compositions comprising copolymers of vinyl pyrrolidone and vinyl acetate as surface stabilizers;” U.S. Pat. No. 6,976,647 for “System and Method for Milling Materials;” and U.S. Pat. No. 6,991,191 for “Method of Using a Small Scale Mill;” all of which are specifically incorporated by reference. In addition, U.S. Patent Application No. 20020012675 Al, published on Jan. 31, 2002, for “Controlled Release Nanoparticulate Compositions,” describes nanoparticulate compositions and is specifically incorporated by reference. None of these references describe compositions of nanoparticulate bisphosphonates, nanoparticulate alendronate, nanoparticulate pamidronate, or nanoparticulate risedronate.
Amorphous small particle compositions are described, for example, in U.S. Pat. No. 4,783,484 for “Particulate Composition and Use Thereof as Antimicrobial Agent;” U.S. Pat. No. 4,826,689 for “Method for Making Uniformly Sized Particles from Water-Insoluble Organic Compounds;” U.S. Pat. No. 4,997,454 for “Method for Making Uniformly-Sized Particles From Insoluble Compounds;” U.S. Pat. No. 5,741,522 for “Ultrasmall, Non-aggregated Porous Particles of Uniform Size for Entrapping Gas Bubbles Within and Methods;” and U.S. Pat. No. 5,776,496, for “Ultrasmall Porous Particles for Enhancing Ultrasound Back Scatter” all of which are specifically incorporated herein by reference.
There is a need for compositions of bisphosphonates, such as alendronate, pamidronate, and risedronate, that have enhanced bioavailability and reduced adverse side effects, including reduced gastrointestinal irritation. The present invention satisfies these needs.